Sit on seat of arched bench with dumbbell on lower thigh. Kick dumbbell up to shoulder while lying back on bench. Grasp both hands under inner plate of dumbbell. Position dumbbell over chest with elbows slightly bent.
Keeping elbows slightly bent throughout movement, lower dumbbell over and beyond head until upper arms are in-line with torso. Pull dumbbell up and over chest. Repeat.
Actual range of motion is dependent upon individual shoulder flexibility. Keep elbows fixed at small bend throughout exercise. See suggested mount & dismount.